Without limiting the scope of the invention, its background is described in connection with orthopedic fracture reduction and stabilization scaffolding as an example. Pelvic fractures are complex injuries with significant associated morbidity and mortality. Surgical management of pelvic fractures is challenging.
Generally, the pelvic ring consists of 2 innominate bones connected anteriorly at the symphysis pubis and posteriorly to the sacrum. The pelvic bones are held in position by strong ligaments that connect the sacrum and ilium; that connect the sacrum and ischium; that connect the 2 pubic bones at the symphysis pubis (a movable articular joint without a synovial membrane); and that connect the sacrum and coccyx. In addition to holding the pelvic bones into position, the ligaments stabilize the pelvis and assist and/or resist in movement, rotation, external rotation forces, sagittal plane rotational deformities and vertical shearing of the pelvis. In addition, several important muscle groups are about the pelvis to impart stability to the pelvic ring, e.g., muscles of the pelvic floor, the levator ani muscle, the piriformis muscle and the coccygeus muscles.
Pelvic fractures are generally the result of severe trauma and blunt impacts on the pelvic girdle, which occur most often, for example, as a result of traffic accidents or falls. Patients who sustain pelvic ring disruptions are at risk for a myriad of acute and long term complications, such as exsanguinating hemorrhage, neurologic dysfunction, sexual dysfunction, leg length discrepancy, chronic pain, thrombo-embolic disease, chronic low back pain, limp and poor functional outcome. As such, patients must be transported to trauma centers for immediate surgical intervention as pelvic fractures are often accompanied by massive blood loss and internal bleeding that may result in death. In addition to the pelvic fracture, many patients present associated primary organ system injuries. Therefore, it is necessary to stabilize a fractured pelvis to reduce further bleeding and injury. Recent advances in treatment of these difficult injuries include the use of percutaneous methods of pelvic fracture stabilization.
Treatments require the fractured pelvic bones to be physically moved and aligned. The ligaments and muscles of the pelvis resist the movement and alignment of the pelvic bones. External fixation devices may be attached to the fractured bones and aid in the alignment and may be used to hold them in position until the patient is stable enough to undergo internal fixation surgical procedures. Once aligned, internal fixation is then used to provide stabilization for the pelvic ring fractures as the bones heal.
Currently, the technique of percutaneous screw fixation of pelvic ring disruptions involves the use of instruments placed against or into the bone through small incisions, guided by fluoroscopy. These instruments are used to re-align fractured bones while definitive stabilization is obtained using percutaneously placed cannulated screws. Successful percutaneous stabilization requires that the surgeons achieve and maintain an acceptable reduction, or alignment, of the injured bone while a screw is passed across the fracture. In most cases, manual traction on the leg is used to achieve fracture reduction. In many cases, metal surgical instruments are introduced through small stab incisions in order to push or pull the bone, to improve alignment. In all cases, fracture reduction is achieved through use of manual pressure by the surgeon's arms, or by traction applied through pins placed into the patient's bones. The pressure required to correct the fracture deformity is often substantial, since deforming forces acting on the fracture include major muscle groups about the patient's hip, lower abdomen and back.
While the surgeon or surgical assistant holds the reduction, another surgeon must accurately place a guide wire over which a cannulated screw will pass. Errant wire or screw placement can injure surrounding nerves, vessels or viscera. Placement of the guide wire and screw rely upon multi-planar fluoroscopic imaging to ensure accuracy. Thus, the surgical team includes of one or more surgeons focused on achieving and holding a perfect reduction, one surgeon focused on accurate, rapid placement of a guide wire and screw, and a skilled radiology technician moving a fluoroscope into multiple positions to ensure reduction is perfect and screw placement is accurate.
Traditional skeletal traction using a metal pin in the tibia or femur is sometimes used to improve alignment of pelvic fractures. Some currently marketed “fracture tables” are designed for this type of use. However, uni-planar longitudinal traction on the leg is often not sufficient to achieve perfect reduction of the fracture. Most pelvic fractures are not displaced in a single plane in line with the leg. Longitudinal traction may offer gross corrections of some displacements, but in most cases, multi-planar corrections are necessary. And since fracture tables do not allow the intact portions of the pelvis to be anchored into place, the pull of traction often results in an unacceptable tilt of the pelvis.
The foregoing problems have been recognized for many years and while numerous solutions have been proposed, none of them adequately address all of the problems in a single device, e.g., skeletal traction to improve alignment of pelvic fractures.